江苏省243项灭螺工程的费用-效果评价

目的：评价243项灭螺工程费用-效果，为今后灭螺工作提供科学指导。方法：采用现场调查的方法，比较灭螺工程实施前后螺情变化，计算直接投入，以有螺面积下降率作为灭螺效果评价指标，并以有螺面积下降1个百分点的费用为单位进行费用-效果分析。结果：实施灭螺后有螺面积下降率为78.68％，其中江滩地区下降59.93％，其它地区均下降93％以上，不同地区灭螺的费用-效果有较大差别。结果显示药物灭螺有较好的费用-效果，而环境改造灭螺效果好，但费用较大，且费用随环乞讨程度的提高而增加。结论：不同地区不同方法灭螺费用-效果受多种因素影响，灭螺规划必须因地制宜。

EVALUATION ON THE COST-EFFECTIVENESS OF THE 243 SNAIL CONTROL PROJECTS IN JIANGSU PROVINCE

Objective To evaluate the cost-effectiveness of the 243 snail control projects in order to provide scientific basis for the snail control in the future. Methods Field investigations were carried out. Changes of the snail habitat areas were compared before and after implementing the 243 snail control projects. The direct costs of the snail control projects were calculated. The reduction rate of the snail-ridden area was regarded as the evaluation index of the effectiveness of the snail control. The costs for reduction of 1% snail-ridden area were used as an unit for cost-effectiveness analysis. Results The areas of the snail-ridden have reduced by 78.68% after implementing the snail control projects. They have reduced by 59.93% in the regions along the Yangtze River. But the reduction rate of the snail-ridden area was more than 93% in the other regions. There were considerable differences for the cost-effectiveness of the snail control projects in the different types of regions. There was the better cost-effectiveness for the snail control with the molluscicide. The effectiveness of the snail control by the environmental modification was well, but the costs were big. And the costs were increasing with the degree of environmental modification. Conclusion The cost-effectiveness of the snail control was influenced by some factors with the different methods and in the different regions. So the plan of the snail control must be suited to the local conditions.